Abstract: This paper presents an efﬁcient method to determine a set of observers (that is, where to site them) such
that a given percentage of a terrain is visually covered. Our method extends the method proposed in (Franklin,
2002) including a local search heuristic efﬁciently implemented using dynamic programming and GPU parallel
programming. This local search strategy allows to achieve a higher coverage using the same number of
observers as the original method and thus it is possible to obtain a given coverage using a smaller number of
observers. It can be an important improvement since an observer can represent an expensive facility such as a
telecommunication tower. The proposed method performance was compared with that of other methods and
the tests showed that it can be more than 1200 times faster than the sequential implementation (with no use
of dynamic programming and no GPU parallel programmming) and, also, more than 20 times faster than a
previous parallel method presented in (Magalhães et al., 2011).(More)

This paper presents an efﬁcient method to determine a set of observers (that is, where to site them) suchthat a given percentage of a terrain is visually covered. Our method extends the method proposed in (Franklin,2002) including a local search heuristic efﬁciently implemented using dynamic programming and GPU parallelprogramming. This local search strategy allows to achieve a higher coverage using the same number ofobservers as the original method and thus it is possible to obtain a given coverage using a smaller number ofobservers. It can be an important improvement since an observer can represent an expensive facility such as atelecommunication tower. The proposed method performance was compared with that of other methods andthe tests showed that it can be more than 1200 times faster than the sequential implementation (with no useof dynamic programming and no GPU parallel programmming) and, also, more than 20 times faster than aprevious parallel method presented in (Magalhães et al., 2011).